A dumb question, but why would a lender (the bank or the vendor) want to be in a situation where the LVR is 100%?
The $500K property is security for $400K to the bank and $100K to the vendor.
I have no real knowledge of 2nd mortgages so is the bank more entitled to the security (as a 1st mortgage) than the Vendor, with a 2nd Mortgage, if something goes wrong?